An experimental study was made on 118 rabbits aimed at restoring bone growth after partial epiphyseal closure. In a first stage, a partial epiphyseal closure was made at the level of the lower femoral growth plate by excision of the growth cartilage and insertion of a bone graft. In a second stage, the bony bridge was removed and a segment of iliac crest growth cartilage was transplanted. It was concluded, on the basis of radiographic and histological studies that the best results were obtained when the growth cartilage was transplanted alone or with a thin layer of bone. The results were poor when the layer of bone transplanted with the cartilage was too thick.